[AAI-26] Adding gizmo data to the repository.

Change-Id: I183f837d45acbfe3c673fde1acf8768d5e3fd37b
Signed-off-by: Shwetank Dave <shwetank.dave@amdocs.com>

2 files changed, 888 insertions, 0 deletions

diff --git a/src/main/java/org/openecomp/crud/dao/GraphDao.java b/src/main/java/org/openecomp/crud/dao/GraphDao.java
new file mode 100644
index 0000000..20b568c
--- /dev/null
+++ b/src/main/java/org/openecomp/crud/dao/GraphDao.java
@@ -0,0 +1,138 @@
+/**
+ * ============LICENSE_START=======================================================
+ * Gizmo
+ * ================================================================================
+ * Copyright © 2017 AT&T Intellectual Property.
+ * Copyright © 2017 Amdocs
+ * All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ *
+ * ECOMP is a trademark and service mark of AT&T Intellectual Property.
+ */
+package org.openecomp.crud.dao;
+
+import org.openecomp.crud.entity.Edge;
+import org.openecomp.crud.entity.Vertex;
+import org.openecomp.crud.exception.CrudException;
+
+import java.util.List;
+import java.util.Map;
+
+public interface GraphDao {
+
+  public Vertex getVertex(String id, String type) throws CrudException;
+
+  /**
+   * Retrieve all of the edges which are incident to the vertex with the specified identifier.
+   *
+   * @param id - The unique identifier of the vertex to retrieve the edges for.
+   * @return - A collection of edges.
+   * @throws CrudException
+   */
+  public List<Edge> getVertexEdges(String id) throws CrudException;
+
+  /**
+   * Retrieve a collection of {@link Vertex} objects which match the supplied type label
+   * and filter properties.
+   *
+   * @param type   - The vertex type that we want to retrieve.
+   * @param filter - The parameters to filter our results by.
+   * @return - A collection of vertices.
+   * @throws CrudException
+   */
+  public List<Vertex> getVertices(String type, Map<String, Object> filter) throws CrudException;
+
+  /**
+   * Retrieve an {@link Edge} from the graph database by specifying its unique identifier.
+   *
+   * @param id - The unique identifier for the Edge to be retrieved.
+   * @return - The Edge corresponding to the specified identifier.
+   * @throws CrudException
+   */
+  public Edge getEdge(String id, String type) throws CrudException;
+
+  /**
+   * Retrieve a collection of {@link Edge} objects with a given type and which match a set of
+   * supplied filter parameters.
+   *
+   * @param type   - The type of edges that we are interested in.
+   * @param filter - The parameters that we want to filter our edges by.
+   * @return - A collection of edges which match the supplied filter parameters.
+   * @throws CrudException
+   */
+  public List<Edge> getEdges(String type, Map<String, Object> filter) throws CrudException;
+
+  /**
+   * Insert a new {@link Vertex} into the graph data store.
+   *
+   * @param type       - The type label to assign to the vertex.
+   * @param properties - The properties to associated with this vertex.
+   * @return - The {@link Vertex} object that was created.
+   * @throws CrudException
+   */
+  public Vertex addVertex(String type, Map<String, Object> properties) throws CrudException;
+
+  /**
+   * Updates an existing {@link Vertex}.
+   *
+   * @param id         - The unique identifier of the vertex to be updated.
+   * @param properties - The properties to associate with the vertex.
+   * @return - The udpated vertex.
+   * @throws CrudException
+   */
+  public Vertex updateVertex(String id, String type, Map<String, Object> properties)
+      throws CrudException;
+
+  /**
+   * Removes the specified vertex from the graph data base.
+   *
+   * <p>NOTE: The vertex MUST contain NO incident edges before it can be deleted.
+   *
+   * @param id - The unique identifier of the vertex to be deleted.
+   * @throws CrudException
+   */
+  public void deleteVertex(String id, String type) throws CrudException;
+
+  /**
+   * Adds an edge to the graph database.
+   *
+   * @param type       - The 'type' label to apply to the edge.
+   * @param source     - The source vertex for this edge.
+   * @param target     - The target vertex for this edge.
+   * @param properties - The properties map to associate with this edge.
+   * @return - The {@link Edge} object that was created.
+   * @throws CrudException
+   */
+  public Edge addEdge(String type, Vertex source, Vertex target, Map<String, Object> properties)
+      throws CrudException;
+
+  /**
+   * Updates an existing {@link Edge}.
+   *
+   * @param id         - The unique identifier of the edge to be updated.
+   * @param properties - The properties to associate with the edge.
+   * @return - The update edge.
+   * @throws CrudException
+   */
+  public Edge updateEdge(Edge edge) throws CrudException;
+
+  /**
+   * Remove the specified edge from the graph data base.
+   *
+   * @param id - The unique identifier of the edge to be deleted.
+   * @throws CrudException
+   */
+  public void deleteEdge(String id, String type) throws CrudException;
+}
diff --git a/src/main/java/org/openecomp/crud/dao/champ/ChampDao.java b/src/main/java/org/openecomp/crud/dao/champ/ChampDao.java
new file mode 100644
index 0000000..ff0a332
--- /dev/null
+++ b/src/main/java/org/openecomp/crud/dao/champ/ChampDao.java
@@ -0,0 +1,750 @@
+/**
+ * ============LICENSE_START=======================================================
+ * Gizmo
+ * ================================================================================
+ * Copyright © 2017 AT&T Intellectual Property.
+ * Copyright © 2017 Amdocs
+ * All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ *
+ * ECOMP is a trademark and service mark of AT&T Intellectual Property.
+ */
+package org.openecomp.crud.dao.champ;
+
+import org.openecomp.aai.champ.ChampAPI;
+import org.openecomp.aai.champ.ChampGraph;
+import org.openecomp.aai.champ.exceptions.ChampMarshallingException;
+import org.openecomp.aai.champ.exceptions.ChampObjectNotExistsException;
+import org.openecomp.aai.champ.exceptions.ChampRelationshipNotExistsException;
+import org.openecomp.aai.champ.exceptions.ChampSchemaViolationException;
+import org.openecomp.aai.champ.exceptions.ChampUnmarshallingException;
+import org.openecomp.aai.champ.graph.impl.TitanChampGraphImpl;
+import org.openecomp.aai.champ.model.ChampObject;
+import org.openecomp.aai.champ.model.ChampRelationship;
+import org.openecomp.aai.champ.model.fluent.object.ObjectBuildOrPropertiesStep;
+import org.openecomp.cl.api.Logger;
+import org.openecomp.cl.eelf.LoggerFactory;
+import org.openecomp.crud.dao.GraphDao;
+import org.openecomp.crud.entity.Edge;
+import org.openecomp.crud.entity.Vertex;
+import org.openecomp.crud.exception.CrudException;
+import org.openecomp.crud.logging.CrudServiceMsgs;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Properties;
+import java.util.Random;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+
+/**
+ * This is the integration layer between the CRUD API service and the low level Champ library
+ * for graph database interaction.
+ */
+public class ChampDao implements GraphDao {
+
+  public static final String CONFIG_STORAGE_BACKEND = "storage.backend";
+  public static final String CONFIG_STORAGE_BACKEND_DB = "storage.backend.db";
+  public static final String STORAGE_HBASE_DB = "hbase";
+  public static final String STORAGE_CASSANDRA_DB = "cassandra";
+  public static final String CONFIG_STORAGE_HOSTNAMES = "storage.hostnames";
+  public static final String CONFIG_STORAGE_PORT = "storage.port";
+  public static final String CONFIG_HBASE_ZNODE_PARENT = "storage.hbase.ext.zookeeper.znode.parent";
+  public static final String CONFIG_GRAPH_NAME = "graph.name";
+  public static final String GRAPH_UNQ_INSTANCE_ID_SUFFIX = "graph.unique-instance-id-suffix";
+
+  public static final String CONFIG_EVENT_STREAM_PUBLISHER = "event.stream.publisher";
+  public static final String CONFIG_EVENT_STREAM_NUM_PUBLISHERS = "event.stream.num-publishers";
+
+
+  public static final String DEFAULT_GRAPH_NAME = "default_graph";
+
+  /**
+   * Set of configuration properties for the DAI.
+   */
+  private Properties daoConfig;
+
+  /**
+   * Instance of the API used for interacting with the Champ library.
+   */
+  private ChampGraph champApi = null;
+
+  private Logger logger = LoggerFactory.getInstance().getLogger(ChampDao.class.getName());
+
+
+  /**
+   * Creates a new instance of the ChampDao.
+   *
+   * @param config - Set of configuration properties to be applied to this instance
+   *               of the DAO.
+   */
+  public ChampDao(Properties config) {
+
+    // Store the configuration properties.
+    daoConfig = config;
+
+    // Apply the configuration to the DAO.
+    configure();
+
+  }
+
+
+  @Override
+  public Vertex getVertex(String id, String type) throws CrudException {
+
+    try {
+
+      if (logger.isDebugEnabled()) {
+        logger.debug("getVertex with id: " + id);
+      }
+
+      long idAsLong = Long.parseLong(id);
+
+      // Request the vertex from the graph db.
+      Optional<ChampObject> retrievedVertex = champApi.retrieveObject(idAsLong);
+
+      // Did we find it?
+      if (retrievedVertex.isPresent() && retrievedVertex.get().getProperties()
+          .get(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName())!=null && retrievedVertex.get().getProperties()
+          .get(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName()).toString()
+          .equalsIgnoreCase(type)) {  
+        
+        // Yup, convert it to a Vector object and return it.
+        return vertexFromChampObject(retrievedVertex.get(),type);
+
+      } else {
+
+        // We didn't find a vertex with the supplied id, so just throw an
+        // exception.
+        throw new CrudException("No vertex with id " + id + " found in graph",
+            javax.ws.rs.core.Response.Status.NOT_FOUND);
+      }
+
+    } catch (ChampUnmarshallingException e) {
+
+      // Something went wrong - throw an exception.
+      throw new CrudException(e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+
+  @Override
+  public List<Edge> getVertexEdges(String id) throws CrudException {
+
+    if (logger.isDebugEnabled()) {
+      logger.debug("get Edges incident to vertex with id: " + id + " from graph");
+    }
+
+    try {
+      long idAsLong = Long.parseLong(id); // GDF - what to do about id???
+
+      // Request the vertex from the graph db.
+      Optional<ChampObject> retrievedVertex = champApi.retrieveObject(idAsLong);
+
+      // Did we find it?
+      if (retrievedVertex.isPresent()) {
+
+        // Query the Champ library for the edges which are incident to the specified
+        // vertex.
+        Stream<ChampRelationship> relationships =
+            champApi.retrieveRelationships(retrievedVertex.get());
+
+        // Build an edge list from the result stream.
+        List<Edge> edges = new ArrayList<Edge>();
+        relationships.forEach(r -> edges.add(edgeFromChampRelationship(r)));
+
+        return edges;
+
+      } else {
+
+        // We couldn't find the specified vertex, so throw an exception.
+        throw new CrudException("No vertex with id " + id + " found in graph",
+            javax.ws.rs.core.Response.Status.NOT_FOUND);
+      }
+
+    } catch (ChampUnmarshallingException e) {
+
+      // Something went wrong, so throw an exception.
+      throw new CrudException(e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+
+    } catch (ChampObjectNotExistsException e) {
+
+      // We couldn't find the specified vertex, so throw an exception.
+      throw new CrudException("No vertex with id " + id + " found in graph",
+          javax.ws.rs.core.Response.Status.NOT_FOUND);
+    }
+  }
+
+
+  @Override
+  public Vertex addVertex(String type, Map<String, Object> properties) throws CrudException {
+
+    if (logger.isDebugEnabled()) {
+      logger.debug("Add/update vertex: {label: " + type
+          + " properties:" + propertiesMapToString(properties));
+    }
+
+    //Add the aai_node_type so that AAI can read the data created by gizmo
+    properties.put(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName(), type);
+
+    // Create an object to represent our vertex in the format expected by the Champ library.
+    ChampObject objectToCreate = buildChampObject(type, properties);
+
+    try {
+
+      // Ask the Champ library to store our vertex, placing the returned object into a
+      // list so that we can easily put that into our result object.
+      return vertexFromChampObject(champApi.storeObject(objectToCreate),type);
+
+    } catch (ChampMarshallingException
+        | ChampSchemaViolationException
+        | ChampObjectNotExistsException e) {
+
+      // Something went wrong - throw an exception.
+      throw new CrudException(e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+
+  @Override
+  public Vertex updateVertex(String id, String type, Map<String, Object> properties)
+      throws CrudException {
+
+    if (logger.isDebugEnabled()) {
+      logger.debug("Update vertex with id: " + id + " with properties: "
+          + propertiesMapToString(properties));
+    }
+    //Add the aai_node_type so that AAI can read the data created by gizmo
+    properties.put(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName(), type);
+
+    try {
+      // Now, build the updated version of the Champ Object...
+      ChampObject updateObject = buildChampObject(id, type, properties);
+      // ...and send it to the Champ library.
+      return vertexFromChampObject(champApi.replaceObject(updateObject),type);
+
+    } catch (ChampObjectNotExistsException e) {
+      throw new CrudException("Not Found", javax.ws.rs.core.Response.Status.NOT_FOUND);
+    } catch (NumberFormatException | ChampMarshallingException | ChampSchemaViolationException e) {
+      throw new CrudException(e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+
+  }
+
+
+  @Override
+  public List<Vertex> getVertices(String type, Map<String, Object> filter) throws CrudException {
+
+    if (logger.isDebugEnabled()) {
+      logger.debug("Retrieve vertices with type label: " + type + " which map query parameters: "
+          + propertiesMapToString(filter));
+    }
+
+
+    filter.put(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName(), type);
+
+
+    Stream<ChampObject> retrievedVertices = champApi.queryObjects(filter);
+
+    List<Vertex> vertices = retrievedVertices
+        .map(v -> vertexFromChampObject(v,type))
+        .collect(Collectors.toList());
+
+
+    if (logger.isDebugEnabled()) {
+      logger.debug("Resulting vertex list: " + retrievedVertices);
+    }
+
+    // ...and return it to the caller.
+    return vertices;
+  }
+
+  private Object getRelKey(String id) {
+    Object key = id;
+    // convert into Long if applicable . TODO : revisit in story NUC-304
+    try {
+      key = Long.parseLong(id);
+    } catch (NumberFormatException e) {
+      // The id isn't a Long, leave it as a string
+    }
+
+    return key;
+  }
+
+  @Override
+  public Edge getEdge(String id, String type) throws CrudException {
+
+    if (logger.isDebugEnabled()) {
+      logger.debug("Get edge with id: " + id);
+    }
+
+    try {
+
+      // Request the edge from the graph db.
+      Optional<ChampRelationship> relationship = champApi.retrieveRelationship(getRelKey(id));
+
+      // Did we find it?
+      if (relationship.isPresent() && relationship.get().getType().equals(type)) {
+
+        // Yup - return the result.
+        return edgeFromChampRelationship(relationship.get());
+
+      } else {
+
+        // We didn't find an edge with the supplied id, so throw an exception.
+        throw new CrudException("No edge with id " + id + " found in graph",
+            javax.ws.rs.core.Response.Status.NOT_FOUND);
+      }
+
+    } catch (ChampUnmarshallingException e) {
+
+      // Something went wrong, so throw an exception.
+      throw new CrudException(e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+  @Override
+  public Edge addEdge(String type,
+                      Vertex source,
+                      Vertex target,
+                      Map<String, Object> properties) throws CrudException {
+
+    // For now, assume source and target are straight ids...
+    try {
+
+      Optional<ChampObject> sourceObject
+          = champApi.retrieveObject(Long.parseLong(source.getId().get()));
+      if (!sourceObject.isPresent() || !sourceObject.get().getType().equals(source.getType())) {
+        throw new CrudException("Error creating edge - source vertex with id " + source
+            + " does not exist in graph data base",
+            javax.ws.rs.core.Response.Status.BAD_REQUEST);
+      }
+
+      Optional<ChampObject> targetObject
+          = champApi.retrieveObject(Long.parseLong(target.getId().get()));
+      if (!targetObject.isPresent() || !targetObject.get().getType().equals(target.getType())) {
+        throw new CrudException("Error creating edge - target vertex with id " + target
+            + " does not exist in graph data base",
+            javax.ws.rs.core.Response.Status.BAD_REQUEST);
+      }
+
+      // Now, create the ChampRelationship object for our edge and store it in
+      // the graph database.
+      return edgeFromChampRelationship(
+          champApi.storeRelationship(
+              new ChampRelationship.Builder(sourceObject.get(), targetObject.get(), type)
+                  .properties(properties)
+                  .build()));
+
+    } catch (ChampMarshallingException
+        | ChampObjectNotExistsException
+        | ChampSchemaViolationException
+        | ChampRelationshipNotExistsException
+        | ChampUnmarshallingException e) {
+
+      throw new CrudException("Error creating edge: " + e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+
+  @Override
+  public List<Edge> getEdges(String type, Map<String, Object> filter) throws CrudException {
+
+    filter.put(ChampRelationship.ReservedPropertyKeys.CHAMP_RELATIONSHIP_TYPE.toString(), type);
+
+    Stream<ChampRelationship> retrievedRelationships = champApi.queryRelationships(filter);
+    // Process the result stream from the Champ library into an Edge list, keeping only
+    // edges of the specified type.
+    List<Edge> edges = retrievedRelationships
+        .map(r -> edgeFromChampRelationship(r))
+        .collect(Collectors.toList());
+
+    return edges;
+  }
+
+  @Override
+  public Edge updateEdge(Edge edge) throws CrudException {
+
+    if (logger.isDebugEnabled()) {
+      logger.debug("Update edge with id: " + edge.getId() + " with properties: "
+          + propertiesMapToString(edge.getProperties()));
+    }
+
+    try {
+      // Now, build the updated version of the Champ Relationship...
+      ChampRelationship updateRelationship = new ChampRelationship.Builder(
+          buildChampObject(edge.getSource().getId().get(), edge.getSource().getType(),
+              edge.getSource().getProperties()),
+          buildChampObject(edge.getTarget().getId().get(), edge.getTarget().getType(),
+              edge.getTarget().getProperties()),
+          edge.getType()).key(getRelKey(edge.getId().get()))
+          .properties(edge.getProperties()).build();
+      // ...and send it to the Champ library.
+      return edgeFromChampRelationship(champApi.replaceRelationship(updateRelationship));
+
+
+    } catch (ChampRelationshipNotExistsException ex) {
+      throw new CrudException("Not Found", javax.ws.rs.core.Response.Status.NOT_FOUND);
+    } catch (NumberFormatException | ChampUnmarshallingException | ChampMarshallingException
+        | ChampSchemaViolationException ex) {
+
+      throw new CrudException(ex.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+  @Override
+  public void deleteVertex(String id, String type) throws CrudException {
+
+    try {
+
+      // First, retrieve the vertex that we intend to delete.
+      Optional<ChampObject> retrievedVertex = champApi.retrieveObject(Long.parseLong(id));
+
+      // Did we find it?
+      if (!retrievedVertex.isPresent() || !retrievedVertex.get().getType().equals(type)) {
+        throw new CrudException("Failed to delete vertex with id: "
+            + id + " - vertex does not exist.",
+            javax.ws.rs.core.Response.Status.NOT_FOUND);
+      }
+
+      // Now, verify that there are no edges incident to the vertex (they must be deleted
+      // first if so).
+      Stream<ChampRelationship> relationships =
+          champApi.retrieveRelationships(retrievedVertex.get());
+
+      if (relationships.count() > 0) {
+        throw new CrudException("Attempt to delete vertex with id "
+            + id + " which has incident edges.",
+            javax.ws.rs.core.Response.Status.BAD_REQUEST);
+      }
+
+      // Finally, we can attempt to delete our vertex.
+      champApi.deleteObject(Long.parseLong(id));
+
+
+    } catch (NumberFormatException
+        | ChampUnmarshallingException
+        | ChampObjectNotExistsException e) {
+
+      throw new CrudException(e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+  @Override
+  public void deleteEdge(String id, String type) throws CrudException {
+
+    try {
+
+      // First, retrieve the edge that we want to delete.
+      Optional<ChampRelationship> relationshipToDelete
+          = champApi.retrieveRelationship(getRelKey(id));
+
+
+      // Did we find it?
+      if (!relationshipToDelete.isPresent() || !relationshipToDelete.get().getType().equals(type)) {
+        throw new CrudException("Failed to delete edge with id: " + id + " - edge does not exist",
+            javax.ws.rs.core.Response.Status.NOT_FOUND);
+      }
+
+      // Now we can delete the edge.
+      champApi.deleteRelationship(relationshipToDelete.get());
+
+    } catch (ChampRelationshipNotExistsException
+        | NumberFormatException
+        | ChampUnmarshallingException e) {
+
+      throw new CrudException(e.getMessage(),
+          javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+
+  /**
+   * This helper method generates a string representation of a properties map for
+   * logging purposes.
+   *
+   * @param properties - The properties map to be converted.
+   * @return - The log statement friendly conversion of the properties map.
+   */
+  private String propertiesMapToString(Map<String, Object> properties) {
+
+    StringBuilder sb = new StringBuilder();
+    sb.append("{");
+
+    for (String key : properties.keySet()) {
+      sb.append("(").append(key).append(" -> ").append(properties.get(key)).append(") ");
+    }
+
+    sb.append("}");
+
+    return sb.toString();
+  }
+
+
+  /**
+   * This helper method constructs a {@link ChampObject} suitable for passing to the Champ library.
+   *
+   * @param type       - The type to assign to our ChampObject
+   * @param properties - The set of properties to assign to our ChampObject
+   * @return - A populated ChampObject
+   */
+  private ChampObject buildChampObject(String type, Map<String, Object> properties) {
+
+    ObjectBuildOrPropertiesStep objectInProgress = ChampObject.create()
+        .ofType(type)
+        .withoutKey();
+
+    for (String key : properties.keySet()) {
+      objectInProgress.withProperty(key, properties.get(key));
+    }
+    return objectInProgress.build();
+  }
+
+
+  /**
+   * This helper method constructs a {@link ChampObject} suitable for passing to the Champ library.
+   *
+   * @param id         - Unique identifier for this object.
+   * @param type       - The type to assign to our ChampObject
+   * @param properties - The set of properties to assign to our ChampObject
+   * @return - A populated ChampObject
+   */
+  private ChampObject buildChampObject(String id, String type, Map<String, Object> properties) {
+
+    ObjectBuildOrPropertiesStep objectInProgress = ChampObject.create()
+        .ofType(type)
+        .withKey(Long.parseLong(id));
+
+    for (String key : properties.keySet()) {
+      objectInProgress.withProperty(key, properties.get(key));
+    }
+    return objectInProgress.build();
+  }
+
+
+  
+  
+  private Vertex vertexFromChampObject(ChampObject champObject, String type) {
+
+    // Get the identifier for this vertex from the Champ object.
+    Object id = champObject.getKey().orElse("");
+
+    // Start building our {@link Vertex} object.
+    Vertex.Builder vertexBuilder = new Vertex.Builder(type);
+    vertexBuilder.id(id.toString());
+
+    // Convert the properties associated with the Champ object into the form expected for
+    // a Vertex object.
+    for (String key : champObject.getProperties().keySet()) {
+      vertexBuilder.property(key, champObject.getProperties().get(key));
+    }
+
+    // ...and return it.
+    return vertexBuilder.build();
+  }
+
+
+  /**
+   * This helper method converts a {@link ChampRelationship} from the Champ library into an
+   * equivalent {@link Edge} object that is understood by the CRUD Service.
+   *
+   * @param relationship - The ChampRelationship object to be converted.
+   * @return - An Edge object corresponding to the supplied ChampRelationship
+   */
+  private Edge edgeFromChampRelationship(ChampRelationship relationship) {
+
+    // Populate the edge's id, if available.
+    Object relationshipId = relationship.getKey().orElse("");
+
+    Edge.Builder edgeBuilder = new Edge.Builder(relationship.getType())
+        .id(relationshipId.toString());
+    edgeBuilder.source(vertexFromChampObject(relationship.getSource(),
+        relationship.getSource().getProperties()
+            .get(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName()) == null
+                ? relationship.getSource().getType()
+                : relationship.getSource().getProperties()
+                    .get(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName()).toString()));
+    edgeBuilder.target(vertexFromChampObject(relationship.getTarget(),
+        relationship.getTarget().getProperties()
+            .get(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName()) == null
+                ? relationship.getTarget().getType()
+                : relationship.getTarget().getProperties()
+                    .get(org.openecomp.schema.OxmModelValidator.Metadata.NODE_TYPE.propertyName()).toString()));
+
+    for (String key : relationship.getProperties().keySet()) {
+      edgeBuilder.property(key, relationship.getProperties().get(key).toString());
+    }
+
+    return edgeBuilder.build();
+  }
+
+
+  /**
+   * Performs all one-time configuration operations which are required when creating
+   * a new instance of the DAO.
+   */
+  private void configure() {
+
+    // Instantiate the Champ library API.
+    try {
+
+      // Determine which back end we are using.
+      switch (getBackendTypeFromConfig()) {
+
+        case IN_MEMORY:
+
+          logger.info(CrudServiceMsgs.INSTANTIATE_GRAPH_DAO,
+              "In Memory",
+              daoConfig.getProperty(CONFIG_GRAPH_NAME, DEFAULT_GRAPH_NAME),
+              "Not applicable");
+
+          champApi = ChampGraph.Factory.newInstance(ChampGraph.Type.IN_MEMORY,
+              daoConfig.getProperty(CONFIG_GRAPH_NAME, DEFAULT_GRAPH_NAME));
+
+          break;
+
+        case TITAN:
+          try {
+            String db = daoConfig.getProperty(CONFIG_STORAGE_BACKEND_DB);
+            Short graphIdSuffix = (short) new Random().nextInt(Short.MAX_VALUE);
+            logger.info(CrudServiceMsgs.TITAN_GRAPH_INFO, GRAPH_UNQ_INSTANCE_ID_SUFFIX
+                + ": = " + graphIdSuffix);
+            if (db.equalsIgnoreCase(STORAGE_CASSANDRA_DB)) {
+              logger.info(CrudServiceMsgs.INSTANTIATE_GRAPH_DAO, "Titan with cassandra backend",
+                  daoConfig.getProperty(CONFIG_GRAPH_NAME, DEFAULT_GRAPH_NAME),
+                  daoConfig.getProperty(CONFIG_STORAGE_HOSTNAMES));
+
+              TitanChampGraphImpl.Builder champApiBuilder =
+                  new TitanChampGraphImpl.Builder(daoConfig.getProperty(CONFIG_GRAPH_NAME,
+                      DEFAULT_GRAPH_NAME))
+                      .property("storage.backend", "cassandrathrift")
+                      .property(GRAPH_UNQ_INSTANCE_ID_SUFFIX, graphIdSuffix)
+                      .property("storage.hostname", daoConfig.get(CONFIG_STORAGE_HOSTNAMES));
+
+              if (daoConfig.containsKey(CONFIG_EVENT_STREAM_PUBLISHER)) {
+                champApiBuilder.property("champ.event.stream.publisher",
+                    daoConfig.get(CONFIG_EVENT_STREAM_PUBLISHER));
+              }
+
+              if (daoConfig.containsKey(CONFIG_EVENT_STREAM_NUM_PUBLISHERS)) {
+                champApiBuilder.property("champ.event.stream.publisher-pool-size",
+                    daoConfig.get(CONFIG_EVENT_STREAM_NUM_PUBLISHERS));
+              }
+
+              champApi = champApiBuilder.build();
+
+            } else if (db.equalsIgnoreCase(STORAGE_HBASE_DB)) {
+
+              logger.info(CrudServiceMsgs.INSTANTIATE_GRAPH_DAO, "Titan with Hbase backend",
+                  daoConfig.getProperty(CONFIG_GRAPH_NAME, DEFAULT_GRAPH_NAME),
+                  daoConfig.getProperty(CONFIG_STORAGE_HOSTNAMES));
+              TitanChampGraphImpl.Builder champApiBuilder =
+                  new TitanChampGraphImpl.Builder(daoConfig
+                      .getProperty(CONFIG_GRAPH_NAME, DEFAULT_GRAPH_NAME))
+                      .property("storage.backend", "hbase")
+                      .property("storage.hbase.ext.zookeeper.znode.parent",
+                          daoConfig.get(CONFIG_HBASE_ZNODE_PARENT))
+                      .property("storage.port", daoConfig.get(CONFIG_STORAGE_PORT))
+                      .property(GRAPH_UNQ_INSTANCE_ID_SUFFIX, graphIdSuffix)
+                      .property("storage.hostname", daoConfig.get(CONFIG_STORAGE_HOSTNAMES));
+
+              if (daoConfig.containsKey(CONFIG_EVENT_STREAM_PUBLISHER)) {
+                champApiBuilder.property("champ.event.stream.publisher",
+                    daoConfig.get(CONFIG_EVENT_STREAM_PUBLISHER));
+              }
+
+              if (daoConfig.containsKey(CONFIG_EVENT_STREAM_NUM_PUBLISHERS)) {
+                champApiBuilder.property("champ.event.stream.publisher-pool-size",
+                    daoConfig.get(CONFIG_EVENT_STREAM_NUM_PUBLISHERS));
+              }
+              champApi = champApiBuilder.build();
+            } else {
+              logger.error(CrudServiceMsgs.INVALID_GRAPH_BACKEND,
+                  daoConfig.getProperty(CONFIG_STORAGE_BACKEND_DB));
+            }
+
+          } catch (com.thinkaurelius.titan.core.TitanException e) {
+
+            logger.error(CrudServiceMsgs.INSTANTIATE_GRAPH_BACKEND_ERR, "Titan", e.getMessage());
+          }
+
+
+          break;
+
+        default:
+          logger.error(CrudServiceMsgs.INVALID_GRAPH_BACKEND,
+              daoConfig.getProperty(CONFIG_STORAGE_BACKEND));
+          break;
+      }
+
+    } catch (CrudException e) {
+      logger.error(CrudServiceMsgs.INSTANTIATE_GRAPH_BACKEND_ERR,
+          daoConfig.getProperty(CONFIG_STORAGE_BACKEND), e.getMessage());
+    }
+  }
+
+
+  /**
+   * Performs any necessary shut down operations when the DAO is no longer needed.
+   */
+  public void close() {
+
+    if (champApi != null) {
+
+      logger.info(CrudServiceMsgs.STOPPING_CHAMP_DAO);
+
+      champApi.shutdown();
+    }
+  }
+
+
+  /**
+   * This helper function converts the 'graph back end type' config parameter into the
+   * corresponding {@link ChampAPI.Type}.
+   *
+   * @return - A {@link ChampAPI.Type}
+   * @throws CrudException
+   */
+  private ChampGraph.Type getBackendTypeFromConfig() throws CrudException {
+
+    // Get the back end type from the DAO's configuration properties.
+    String backend = daoConfig.getProperty(CONFIG_STORAGE_BACKEND, "in-memory");
+
+    // Now, find the appropriate ChampAPI type and return it.
+    if (backend.equals("in-memory")) {
+      return ChampGraph.Type.IN_MEMORY;
+    } else if (backend.equals("titan")) {
+      return ChampGraph.Type.TITAN;
+    }
+
+    // If we are here, then whatever was in the config properties didn't match to a supported
+    // back end type, so just throw an exception and let the caller figure it out.
+    throw new CrudException("Invalid graph backend type '" + backend + "' specified.",
+        javax.ws.rs.core.Response.Status.BAD_REQUEST);
+  }
+
+
+}